Measuring instrument for Thermogravimetrically determining the moisture content of a material

Abstract

A measuring instrument for thermogravimetrically determining the moisture content of a material, which includes a base (12), configured as a balance, with a base surface (22), and a hood (14) pivotably connected to the base. The hood has a weighing chamber lid (50), weighing chamber walls (52-56) and a heating element (44). The hood consists of an electronics module (36) that includes the heating element and an electronic power unit, and of a mechanical module (48) that includes the weighing chamber lid and all of the weighing chamber walls. The mechanical module (48) is rigidly and reversibly coupled to the electronics module so that the heating element, protrudes from a main body (42) of the electronics module and rises through a corresponding opening (58) in the rearward weighing chamber wall (56), with the main body being pivotably connected to the base and surrounding the electronic power unit.

What is claimed is: 
     
       1. A measuring instrument for thermogravimetrically determining a moisture content of a material, comprising
 a base, which is configured as a balance and which has a base surface, which forms at least one weighing chamber floor and through which a weighing pan support passes, and 
 a hood, which is pivotably connected to the base and which forms a weighing chamber lid and a plurality of weighing chamber walls including a rearward weighing chamber wall, as well as at least one heating element, configured to heat the chamber that is formed by the weighing chamber lid and the weighing chamber walls and which is in electrical contact with an electronic power unit,
 wherein the hood comprises an electronics module comprising the heating element and the electronic power unit, and a mechanical module comprising the weighing chamber lid and the plurality of weighing chamber walls, and 
 wherein the mechanical module is rigidly and reversibly coupled to the electronics module such that the heating element, which protrudes from a main body of the electronics module, extends through a corresponding opening in the rearward weighing chamber wall, and the main body is pivotably connected to the base and surrounds the electronic power unit. 
 
 
     
     
       2. The measuring instrument as claimed in  claim 1 , wherein
 in parallel with the heating element, at least one guide rail protrudes from the main body of the electronics module, and the mechanical module is mounted reversibly onto the guide rail with corresponding guide elements. 
 
     
     
       3. The measuring instrument as claimed in  claim 1 , wherein
 the mechanical module has a ring-shaped draft shield, which is arranged in the chamber surrounded by the weighing chamber walls and which in a closed state of the hood surrounds the weighing pan support. 
 
     
     
       4. The measuring instrument as claimed in  claim 1 , wherein
 the main body of the electronics module comprises a coupling detector configured to detect a current state of coupling between the electronics module and the mechanical module. 
 
     
     
       5. The measuring instrument as claimed in  claim 1 , wherein
 the main body of the electronics module comprises a temperature sensor, a pivotal position detector, a lighting device and/or at least one status light. 
 
     
     
       6. The measuring instrument as claimed in  claim 1 , wherein
 the main body of the electronics module comprises an electronic control unit to operate the heating element, the electronic control unit is in communication with a control unit of the balance, and the control unit is arranged in the base. 
 
     
     
       7. The measuring instrument as claimed in  claim 1 , wherein
 the base surface is formed by a removable cover plate that is configured as an at least substantially flat surface. 
 
     
     
       8. The measuring instrument as claimed in  claim 1 , wherein
 the main body of the electronics module is connected to the base via at least one hook-shaped hinge surrounding a rearward edge of the base surface. 
 
     
     
       9. The measuring instrument as claimed in  claim 8 , wherein
 the at least one hook-shaped hinge is reversibly connected to the main body of the electronics module or the base. 
 
     
     
       10. The measuring instrument as claimed in  claim 1 , wherein
 the base surface is formed by a removable cover plate, which rests on a main body of the base. 
 
     
     
       11. The measuring instrument as claimed in  claim 10 , wherein
 the cover plate has a recess, through which the weighing pan support passes and in which a sealing sleeve, which is supported on the surface of the cover plate and is secured in a receptacle of the main body of the base, is arranged. 
 
     
     
       12. The measuring instrument as claimed in  claim 11 , wherein
 the sealing sleeve is secured in the receptacle by a screw or bayonet connection having a height dimensioned to place the connection under a spring bias generated by a diaphragm elasticity of the cover plate and extending in a vertical direction. 
 
     
     
       13. The measuring instrument as claimed in  claim 1 , wherein the corresponding opening extends through the rearward weighing chamber wall from the main body to the chamber. 
     
     
       14. The measuring instrument as claimed in  claim 1 , wherein the heating element is rigidly and reversibly coupled to the main body of the electronics module independent of the rigid and reversible coupling between the mechanical module and the electronics module.